The invention relates to a profile strip of a vehicle body, which profile strip is configured with at least one shell component made from fiber-reinforced plastic and at least one pultrusion component, in which the profile strip is subjected to bending in a bending direction and the pultrusion component is arranged next to the shell component in the bending direction. The pultrusion component is configured with an outer shell and at least one inner web which is coupled thereto on the inside. A similar profile strip is known from DE 10 2010 012 715 A1. Furthermore, the invention relates to the use of a profile strip of this type on a vehicle body.
Vehicle bodies of modern vehicles are configured nowadays with fiber-reinforced plastic. The associated profile strips are as thin-walled as possible for weight reasons and then, correspondingly, have a low rigidity and stability. In particular, an optimum between the available supporting force and the weight required to this end therefore has to be found for profile strips of this type.
According to the invention, a profile strip of a vehicle body is provided, the profile strip being configured with at least one shell component made from fiber-reinforced plastic and at least one pultrusion component, in which the profile strip is subjected to bending in a bending direction and the pultrusion component is arranged next to the shell component in the bending direction. The pultrusion component is configured with an outer shell and at least one inner web which is coupled thereto on the inside. The at least one inner web extends in the bending direction, and the at least one shell component additionally has inner ribs which likewise extend in the bending direction.
A shell component made from fiber-reinforced plastic is to be understood to mean a component which is configured from at least one shell made from plastic as a matrix, in particular synthetic resin in the form of polyester resin or epoxy resin, and reinforcing materials or reinforcing fibers embedded therein. Both thermosetting and thermoplastic polymers can be used as a matrix. The relatively inexpensive polyester resins, vinyl ester resins and epoxy resins are used as thermosetting matrix systems. Thermoplastic fiber composite materials can also be produced. Polyamides, polypropylenes and polyethylenes are then predominantly used as matrix systems. Synthetic fibers made from glass, carbon and aramid are predominantly used as reinforcing material, which can be used as rovings, contextures, woven fabrics or nonwovens. In this way, the properties of the shell-shaped component can be varied both in absolute terms and also in terms of their ratio between its longitudinal and transverse direction within a wide range.
A pultrusion component is to be understood to mean a component which has been produced by means of a pultrusion process. Pultrusion processes are also called extrusion processes. A pultrusion system includes a fiber rack, fiber guides, an impregnating device, a shaping or hardening mold, a pull apparatus and a cutting unit. During the pultrusion process, the fiber rovings are guided over fiber guides from a multiple story reel store into the resin bath, the impregnating device. The fibers run through a plurality of pre-shaping stations, with the result that they are adapted to the desired profile shape. At the fiber guides, mats, woven fabrics, contextures or nonwovens can be integrated into the process, in order to adapt/optimize the mechanical properties with respect to a purely unidirectional reinforcement, as is achieved by way of fibers.
A distinction can be made fundamentally between the following three processes for resin impregnation of reinforcing fibers: tub processes, pull-through processes and injection processes.
In the tub process, the reinforcing fibers are introduced from above and are pulled through an open resin bath, in which the fibers are deflected by way of perforated sheets. This process is the most common for producing pultrusion profiles, in particular with simple cross sections. The impregnation takes place in an open resin bath, through which the dry fibers are pulled. The deflection of the fibers into and out of the resin bath takes place by way of guide plates.
The pull-through process is used, in particular, during the production of profiles with geometrically complex cross sections. The reinforcing fibers are guided without deflection through the resin bath, with the result that the impregnating unit is passed through horizontally. Pre-shaping stations which resemble the later profile shape are situated on the inlet and outlet side of the resin bath. The matrix which is stripped off by way of the fiber guides is collected below the impregnating unit with the aid of a trough.
In the injection process, the reinforcing fibers are guided without deflection through the impregnating mold. The mold has the shape of the profile to be produced and widens in the interior. The resin is injected into the cavity from both sides transversely with respect to the fiber direction. This process is particularly preferred in the present case.
After the end of the resin impregnation, final shaping of the produced profile strip and/or hot curing at temperatures between 100° C. to 200° C. preferably then also take/takes place according to the invention.
The finished profile strip is conveyed continuously by way of an adjoining pulling apparatus, for example in the form of a caterpillar take-off or pneumatic grippers, and is pulled out of the mold at a continuous speed (the English name pultrusion therefore also results from “pull” and “extrusion”). A process speed of from 0.1 m/min to 1.2 m/min is preferred.
According to the invention, furthermore, the so-called radius pultrusion is preferred. In contrast to the standard process, in this process the mold, the cavity of which corresponds to the course of the desired profile, is moved step-by-step over the profile which is being produced. The gripper, only one of which is present in this process, holds the profile fixedly during the forward movement of the mold and releases the produced profile again during the reverse movement of the mold, as shown in the figure concerning the process sequence of the radius pultrusion.
By way of the process and its variants, it is possible to produce profiles which are curved in almost any desired manner and, for example, also helical profiles.
The profile strip is subjected to bending in a bending direction on the associated vehicle body, and the pultrusion component is then arranged next to the shell component in the bending direction. Furthermore, the pultrusion component is configured with an outer shell and at least one inner web which is coupled thereto on the inside, the at least one inner web extending in the bending direction. The embodiments of this type are advantageous, in particular, in order to increase the rigidity in a weight-saving manner of a profile strip which is subjected specifically to bending.
Furthermore, in particular, optionally the shell component and/or the pultrusion component can be filled with foam in order to increase the rigidity of the construction according to the invention. The filling with foam advantageously takes place, in particular, after the production of the components in a separate manufacturing step.
Furthermore, the pultrusion component can advantageously be adhesively bonded over the full surface area to the shell component. The full surface area adhesive bonding of this type couples the two components to one another in such a way that a composite component is produced which has correspondingly high strength values.
Furthermore, the invention is directed specifically to the use of a profile strip according to the invention of this type in a passenger compartment of a vehicle body. Here, the sill of the passenger compartment is particularly preferably formed by way of the profile strip. Here, in particular, the available space in the passenger compartment can be utilized in an optimum manner, by the pultrusion component being configured so as to cover the entire height of the shell component.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.